1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0 2*4882a593Smuzhiyun /* 3*4882a593Smuzhiyun * Purgatory code running between two kernels. 4*4882a593Smuzhiyun * 5*4882a593Smuzhiyun * Copyright IBM Corp. 2018 6*4882a593Smuzhiyun * 7*4882a593Smuzhiyun * Author(s): Philipp Rudo <prudo@linux.vnet.ibm.com> 8*4882a593Smuzhiyun */ 9*4882a593Smuzhiyun 10*4882a593Smuzhiyun #include <linux/kexec.h> 11*4882a593Smuzhiyun #include <linux/string.h> 12*4882a593Smuzhiyun #include <crypto/sha.h> 13*4882a593Smuzhiyun #include <asm/purgatory.h> 14*4882a593Smuzhiyun verify_sha256_digest(void)15*4882a593Smuzhiyunint verify_sha256_digest(void) 16*4882a593Smuzhiyun { 17*4882a593Smuzhiyun struct kexec_sha_region *ptr, *end; 18*4882a593Smuzhiyun u8 digest[SHA256_DIGEST_SIZE]; 19*4882a593Smuzhiyun struct sha256_state sctx; 20*4882a593Smuzhiyun 21*4882a593Smuzhiyun sha256_init(&sctx); 22*4882a593Smuzhiyun end = purgatory_sha_regions + ARRAY_SIZE(purgatory_sha_regions); 23*4882a593Smuzhiyun 24*4882a593Smuzhiyun for (ptr = purgatory_sha_regions; ptr < end; ptr++) 25*4882a593Smuzhiyun sha256_update(&sctx, (uint8_t *)(ptr->start), ptr->len); 26*4882a593Smuzhiyun 27*4882a593Smuzhiyun sha256_final(&sctx, digest); 28*4882a593Smuzhiyun 29*4882a593Smuzhiyun if (memcmp(digest, purgatory_sha256_digest, sizeof(digest))) 30*4882a593Smuzhiyun return 1; 31*4882a593Smuzhiyun 32*4882a593Smuzhiyun return 0; 33*4882a593Smuzhiyun } 34